Our past studies have documented the existence of an oncofetal protein (OFP) in rats with 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat pancreas cancer. The objective of this research is to evaluate the usefulness of this OFP in predicting the presence of tumor cells in the pancreas at an early stage of cancer. The hypothesis to be tested is that, during the initial stages of pancreas cancer, the tumor cells synthesize an OFP that may be used as a tumor marker for clinical identification and localization. To test this, an in vitro determination of the OFP content will be accomplished by conventional radioimmunoassay techniques utilizing a monoclonal antibody and an in vivo ascertainment of cancer cells carried out by means of a radiodetectionassay through localization of this antibody radiolabeled with iodine\-\131. The experimental model will consist of inbred Fischer F344 young male rats exposed to DMBA by implantation of the chemical into the "head" of the pancreas. Such implantation results in over 80% of the animals developing carcinomas of exocrine origin with ductule-like structures in 4 to 6 months. Studies of this animal model will involve: (1) identifying that time and dose of DMBA necessary for developing a sufficient quantity of OFP that is to be detected by the two procedures; and (2) delineating the influence of later metastatic lesions upon the measured results. It is anticipated that our findings may be immediately translated into techniques that will permit a clinical evaluation of patients suspected of harboring pancreatic cancer. (2)